Basic sound level meter, class 2

Brief description:
HD 8701 sound level meter is a portable instrument, easy and quick to use, suitable for measuring industrial and civil noise levels.
The noise levels can be easily read in dB(A) on the large LCD display which also shows all the information concerning the mode of operation of the instrument. One second after switching on and with a resolution of 0.1 dB, the digital reading gives the continuously updated value of the RMS sound pressure level, with a type A frequency weighting. The single range from 30 to 130 dB further simplifies the use of the instrument, as the user does not have to change scale. Through the keyboard the following operations are possible:
Selecting the time constant S/F
Displaying the maximum value recorded "MAX" and zeroing it "RESET MAX", freezing the indication on the display "HOLD"